Internal-combustion engine



June 1s, 1929. 'E J. RUMMLER INTERNAL COMBUSTION ENGINE `Orgina1 Filed May l, 1924v 3 Sheets-Sheet l y June A18, 1929. F. J. RUMMLER INTERNALv COMBUSTION ENGINE Original Filed May l, 1924 3 Sheets-Sheet 2 June 18, 1929. F J, RUMMLER V1,717,811

INTERNAL COMBUSTION ENGINE Orgin'al Filed May l, 1924 3 Sheets-Sheet 3 i 27 Y f' :z f I A Iv 1+ 7 M M i V /z l is 1S a l 2E l l Il 2X vq i Patented June 18, 1929.

UNITED STATES FRANCIS J. RUMMLER, F LYNDHURST, NEW JERSEY.

INTERNAL-COMBUSTION ENG-INE.

Substitute for application Serial No. 710,206, led May 1, 1924. This application led May 1, 1929.

seriai No. 359,681.

The invention relates more particularly to engines of the two-cycle type, and the object of the invention is to provide an engine of this character which shall be simple in construction, of few parts, easily manufactured and assembled, and in which the recognized theoretical advantages of the twocycle motor may be realized and in which the objectionable features inherent in the usual practical examples of this type, are entirely eliminated or their effects greatly reduced.

The invention consists in certain novel feaftures of construction and arrangement by which the above and other objects are at- ]5 tained, to be hereinafter described and claimed.

The accompanying drawings form a part of this specification and show an approved form of the invention.

Figure 1 is a vertical section, partly in elevation, showing the invention as applied to a motor having four cylinders in line; the

plane of section being taken through the axial lines of the cylinders.

Figure 2 is a vertical axial section, taken at a right angle to Figure 1, on the line 2-2 in the latter figure, and partly in elevation.

Figure 3 is a horizontal section, on the line 3 3 in Figure 2.

Figure 4l is a horizontal section, on the line 4.--4 in Figure 2.

Figure 5 is a vert-ical section through the upper portion of one of the cylinders, on a larger scale, illustrating the scavenging action.

Figure 6 is a. vertical section partly in ele-v vation, showing a detail.

Similar reference letters and numerals indicate the same parts in all the figures.

In the eXemplificat-ion of the invention as illustrated in the drawings, four open-ended vertical cylinders are shown, marked respcctively A, B, C and D, shown as formed in one with each other and with the crank case 5 7, and having a head 8 covering the open upper ends. The cylinders and head arc formed with water jackets 9 performing the usual function. The shaft 10 is mounted in r bearings in the crankcase below, and is "0 equipped with four cranks A1, B1, C1 and D1 arranged at an angle of 90O each to the next.

as shown in Figure 1.

Each cylinder contains a movable hollow piston A2, B2 C2 and D2 arranged to reciprocate therein and each having ka piston pin 11 in the skirt of its open lower cnd, joined to its crank by a connecting rod 12.

Each piston is provided with packing rings 13 near its upper closed end, and at such upper end each is contracted to form a tubular axial extension or neck 14; of considerably less diameter than the piston, projecting upwardly through a stuffing boX 15 in the head 8, the tubular gland of which is continued upwardly as a cylindrical dome 16 to receive and inclose thc neck 14- and is closed at the top'by a screw cap 17.

The movable pistons are smoothly bored and finished interiorly to match to stationary pistons 18 received therein and suspended by rods 29 from the upper ends of the domes 16. The rods 29 terminate above each in a ball 19 received in corresponding cavities in the halves of a divided cylindrical block 20 eX- tending into the dome and having a flange 21 lyingupon the top edge thereof and is held in place by the screw cap 17. The ball and socket suspension thus provided permits such slight changes in position laterally as may bc required by the stationary piston.

The necks 14 join their movable pistonsby curved shoulders as at 22, and the heads S contract inwardly conically as at 23. The spaces above the movable pistons A2. B2, C2

and D2 and the angular walls 23 of the head 8 serve as the combustion chambers A3, B3, C3 and D3 of the engine.

In the body or skirt portion of cach movable piston are radial inlet ports 24 arranged at the completion of each upstroke to regisn ter with corresponding` inlet passages 25 in the cylinders and in communication with lan inlet manifold 26 bringing the required eX- plosive mixture of hydrocarbon vapor and air from a carburetor or analogous vaporizer, not shown, to supply the interior of the movable pistons above the pistons 18 and also the interiors of the necks 14 and domes 16 forming the precompression chambers` Delivery ports 27, shown as angularly inclined and circumferentially arranged, are provided near the upper end of each neck, soy located as to permit the escape therethrough to its combustion chamber on the downstroke of the movable piston, the gas being compressed within such pistonabove the stationary piston 18 until the delivery ports 27 descend far enough to permit such escape under pressure.

Exhaust Vports 2.8 in `the cylinders lead to exhaust manifolds 29, shown on both sides of the engine, see Figure 2, and are so located as to be fully uncovered by the shoulders 22 when the movable pistons reach the lowest point in their reciprocations and permit the escape of the spent gases and products of combustion after each explosion in the combustion chambers A, B3, C3 and D3.,

The operation is as follows z-Referring to Figures 1 and 2, the movable piston A2 in the cylinder A is at the end of its upstroke; its inlet ports 24 register with the inlet passages from the inlet manifold 26 and the entire interior of the piston A2 and its neck 14 and interior of its dome 16 are filled with incoming gas at normal temperature. On the down stroke the ports 24 descend out of register, the Vpassages 25 are closed by the skirt of the movable piston A2 and the imprisoned gas is compressed and its temperature and pressure raised untilthe descent of the piston A2 presents the delivery ports 27 in the neck 14 below the stuffing box 15 and in direct communication with the combustion chamber A3. This action serves three purposes; first, it cools the working parts; second, it raises the temperature and pressure of the imprisoned gas; and third, it thoroughly vaporizes the gas.`

The shoulder 22 of the piston A2 has, in advance of this delivery, uncovered the exhaust ports 28 and the exhaust gases from the immediately preceding explosion rushing to the exhaust ports are followed by the incoming fresh charge at an initially slightly greater pressure which aids in this scavenging operation. This increase of pressure obtains only until the pressure in the interior of the movable piston has fallen to that of the exhaust gases during which period the inlet gases are continuing to displace the exhaust gases. This action causes an accelera-A tion in velocity and momentum of the exhaust gases.

On the upstroke the charge of fresh gas in the combustion chamber is compressed ready for ignition and explosion.

In Figure 1, cylinder A and its piston A2 and combustion chamber A3 are in the condition of receiving a charge in the piston or pre-compression chamber, and exploding a charge in the combustion chamber. The crank A1 is on top stroke.

Piston B2 in cylinder B is moving upward on the quarter stroke of the crank B1, compressing a transferred charge in the combustion chamber B3, and inducing a partial vacuum in the piston or precompression chamber preparatory to sucking in a fresh charge of gas; the inlet and exhaust ports and passages are closed.v

Piston C2 in the cylinder C is on the downward quarter stroke of crank C1 during explosion 1in the combustion chamber C3, and compressing a fresh charge in the piston chamber; inlet and exhaust ports and passages are closed.

Piston D2 in cylinder D is at its lowest point in the down stroke of crank D1. The inlet port and passage are closed and the exhaust port uncovered while a fresh charge is entering the combustion chamber D3 through the delivery ports 27 in the neck and driving out the exhaust gases.

The ports 27 are preferably cut angularly as shown, to facilitate 'passage through the stuffingbox 15 but mainly to induce a swirling turbulent movement of the escaping therethrough to the combustion chamber.

It will be noted that the precompression, piston or storage chamber is of a capacity to insure the required supply to the combustion chamber in a highly compressed condition, and that fresh cool gas is in direct contact with the interior of the movable piston bathing its walls and inner surface of its head and also the upper face ofthe fixed piston, A large portion of the exterior surface of the skirt of the movable piston is also thus bathed and cooled by exposure in the wide intake passages 25.

The suspension of the stationary piston from the tubular dome 16 by-a ball and socket joint permits the stationary piston to float and accommodate itself flexibly in axial alinement with the movable piston in which it is contained.

The introduction. of precompressed gas at the top of the combustion chamber, uniformly ldistributed in a blanket above the outgoing spent gases and at a pressure greater than that of such exhaust gases, causes the latter to be completely expelled and the combustion chamber thoroughly scavenged without loss of the fresh charge. Figure 5 shows dia-grammatically the scavenging action; the incoming precompressed gas, indicated by the light dotted arrows, issues from the neck 14 through the angularly arranged delivery ports 27, practically horizontally both from above and below theports 27 and on striking the inclined walls 23 ofthe head 8 are deflected downwardly and uniformly in practically vertical lines in the annular combustion chamber, driving the already rapidly moving exhaust gases, represented by the heavy full line arrows, downwardly and outwardly through ,the wide exhaust ports 28 in the cylinder wall, the change in direction being facilitated by the curved lines of the conical shoulder 22 of the movable piston. As the momentum of the moving exhaust gases and that of the incoming fresh gas are practically equal, all danger of a' rush of such fresh gas directly to an open exhaust port is avoided, and the scavenging operation is fully completed at the closing of the exhaust ports without the loss of fresh gas or forming an undesired mixture of exhaust and fresh gases. Formation of carbon on the underside of the interior of the movable piston is prevented by the absence of oil and heat from such surfaces and the same is true o f the under face of the stationary piston, so that contamination of oil in the crankcase by flakes and particles of carbon falling from above is obviated.

It will be noted that the construction of the motor is simple, the parts are few, and assemblage easy. The objectionable features of the usual types of two-cycle motors are eliminated andthe well known desirable qualities of this simple form of internal combustion engine are attained in marked degree.

By reason of the fact that the only portion of the movable piston extending into t-he lower portion of the cylinder adjacent to vand in communication with the crankcase, is the skirt or thin shell of the movable piston, the displacement of air in such lower portion and crankcase is only that due to the reciprocations of such skirt instead of that due to the reciprocations of a solid piston head as usual, the result being that breather action in the crankcase is so reduced as to be negligible; this permits the crankcase and its connection to the cylinder to form a completely sealed crankcase chamber and eectually prevents the entrance of road dust or other extraneous matter to such chamber.

Although the invention is shown and described as applied to a vertical four in line engine, it will be understood that a greater or less number of cylinders may be employed, differently arranged, and that other modifications in the forms and proportions may be made without departing from the principle of the invention.

I claim:

1. In an internal combustion engine, a cylinder, a head therefor, a movable hollow piston in said cylinder having a depending skirt, and a stationary piston within said movable piston and suspended from said head, there being inlet passages and exhaust ports in said cylinder and an inlet port in said skirt leading to the interior of said movable piston directly from the inlet passage of said cylinder.

2. In an internal combustion engine, a cylinder having inlet passages and exhaust ports, a head for said cylinder having a closed dome thereon, a movable hollow piston in said cylinder having a skirt and controlling said exhaust ports and having an inlet port coacting with said inlet passage, and a stationary piston within said movable piston and suspended from said dome, said inlet passage leading directly to the interior of said movable piston through the inlet port in said skirt.

3. In an internal combustion engine, a cylinder having inlet passages and exhaust ports, a head for said cylinder having a closed dome thereon, a movable hollow piston in said cylinder having a skirt and controlling said exhaust ports and having an inlet port in said skirt coacting with said inlet passage and having a. neck open at the upper end, received in said dome and of smaller diameter than the interior of said dome to provide an annular space surroundingsaid neck, delivery ports in said neck below said open end and controlled by the movements of said neck through said head, a stationary piston within said movable piston, flexibly suspended from said dome, the interior of said movable piston serving as a precompression chamber and the space above said movable piston serving as a combustion chamber and receiving its supply from such precompression chamber through said ports in said neck, whereby both the interior and exterior surfaces of said neck are cooled.

4. In an internal combustion engine, a cylinder, a movable hollow piston therein, a head for said cylinder having an upwardly extended closed dome, a tubular neckon said mov- Y able piston received in said dome and having' its interior open and unobstructed through-- out its length, a stationary piston within said movable piston, and suspending means for said stationary piston extending from the latter through said neck to said dome.

5. In an internal combustion engine, a cylinder, a movable hollow piston in said cylinder, a head for said cylinder having an upwardly extended dome, a tubular neck on said movable piston received in said dome, a socket in said dome, a ball received in such socket, a rod extending from said ball and through said neck to t-he interior of said movable piston, and a stationary piston ixedly attached to and suspended by said rod.

6. In an internal combustion engine, a cylinder, a hollow movable piston therein, having a neck, a head for said cylinder having a dome of larger diameter than said neck and receiving the latter with an annular space between them, a stationary piston within said movable piston, and inlet and delivery ports and passages arranged to supply cool gas to the interior of said movable piston above said stationary piston and to the interior of said neck and to that portion of the exterior of said neck exposed in such space.

7. In an internal combustion engine, a cylinder, a movable hollow piston therein having a skirt, a stationary piston within said movable piston, an inlet passage in the wall of said cylinder immediately above said stationary piston, and a port in said skirt located to register with said passage in one position and to be moved to a position between said stationary piston and wall when out of such register, whereby the interior of said movable piston is doubly sealedby said skirt relatively to said inlet passage.

8. In an internal combustion engine, a cylinder, a head therefor having an upwardly extended dome, a movable hollow piston in said cylinder and having a tubular neck received in said dome, annularly arranged de livery ports in said neck disposed angularly to Ithe axial line of said neck, and a stationary piston received in said movable piston and suspended from said dome.

9. In an internal combustion engine, a cylinder, a head therefor having an upwardly extended dome, a movable hollow` piston in said cylinder and having a tubular neck received in said dome, said neck having its uppei` end open, annularly arranged delivery ports'in said neck, a stationary piston re- 'ceived in said movable piston and suspended from said dome, the space above said stationary piston serving as a precompression chamber and the space between said movable piston and said head serving as a compression chamber, and packing means disposed between said chambers. l

10. In an internal' combustion engine, a cylinder having inlet passages and exhaust ports, ahead for said cylinder having a closed dome thereon, a movable hollow piston in said cylinder having a skirt and controlling said exhaust ports and having an inlet port in said skirt eoaeting with said inlet passage and having a neck open at the upper end, received in said dome, and of smaller diameter than the interior of said dome, to provide an annular space surrounding said neck, delivery ports in said neck below said open end and controlled by the movements of said neck through said head, said delivery ports arranged to deliver gas therethrough and so disposed as to impart swirling turbulent movements to the gas issuing therefrom, a stationary piston within said movable piston, flexibly suspended from said dome, the interior of said movable piston serving as aprecompression chamber and the space above said movable piston serving as a combustion chamber and receiving its supply from such precompression chamber through said delivery ports in said neck, whereby both the interior and exterior surfaces of said neck are cooled.

In testimony that I claim the invention set forth I affix my signature hereto.

FRANCIS J. RUMMLER. 

